1. Field of the Invention
The present invention relates to an optical fiber connector for optically connecting optical fibers, and to an optical fiber connecting method for optically connecting optical fibers using the optical fiber connector.
2. Description of the Related Art
In optical communication and transmission techniques, optical wiring, in which optical transmission lines are formed between LSIs mounted on a board, has recently been developed. In these techniques, the optical transmission lines are formed of, for example, optical fibers or waveguide films. At the present stage, the transmission loss of waveguide films is higher than optical fibers by an order of 3 or 4. Accordingly, to covering a relatively long distance, it is effective to use an optical fiber.
When, for example, LSIs on a board are connected by optical fibers, it is necessary to adjust the lengths of the optical fibers between the LSIs. In this case, it is possible to attach an optical connector to each end of each optical fiber. This is, however, unrealistic since the processing (in particular, polishing) of each end of each optical fiber costs much. Instead, a method called mechanical splicing is effective, in which end faces are formed using stress rupture and no polishing, thereby semi-permanently connecting optical fibers to LSIs.
As a mechanical splicing method, Jpn. Pat. Appln. KOKAI Publication No. 4-124606 discloses a technique for inserting a fiber into a thin tube called a sheath, and crimping the sheath to fix the fiber. Further, Jpn. Pat. Appln. KOKAI Publication No. 2-12112 discloses another mechanical splice method, in which a counter bore for holding an optical fiber is formed in a split sleeve of aluminum, and optical fibers having their end faces formed by stress rupture are made to contact each other in the bore. In this state, the fibers are axially pressed against each other, and the split sleeve is clamped to fix the fibers. This method does not require polishing, and enables optical fibers to be connected on-site using a tool, which does not cost much.
The technique disclosed in Jpn. Pat. Appln. KOKAI Publication No. 4-124606 is disadvantageous in that polishing the connection ends of optical fibers costs much, and in that since each sheath must be crashed, a large tool is needed for it, which makes it difficult to perform connection on-site. Furthermore, since optical fibers are inserted in a sheath and fixed therein, the optical fiber holding portion may be easily displaced by, for example, thermal expansion.
In Jpn. Pat. Appln. KOKAI Publication No. 2-12112, on-site processing is possible. However, since optical fibers contact each other in the aluminum split sleeve, it is necessary to prevent the sleeve from being displaced because of the deformation that occurs when it is clamped. To realize this, it is necessary to increase the strength of the material of the sleeve. This means that it is difficult to form the sleeve of a resin. Further, when the sleeve is formed of a metal, it is inevitably enlarged.